/*
 * Copyright 2002-2012 the original author or authors.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      https://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package org.springframework.aop;

/**
 * 核心Spring的指向性抽象。
 *
 * 一个Pointcut是由一个{@link ClassFilter}和一个{@link MethodMatcher}组成。
 * 这些基本术语和一个Pointcut本身都可以被组合起来以建立组合
 * 例如，通过{@link org.springframework.aop.support.ComposablePointcut}）。
 *
 * @author Rod Johnson
 * @see ClassFilter
 * @see MethodMatcher
 * @see org.springframework.aop.support.Pointcuts
 * @see org.springframework.aop.support.ClassFilters
 * @see org.springframework.aop.support.MethodMatchers
 */
public interface Pointcut {

	/**
	 * 返回这个切点的ClassFilter。
	 * @return the ClassFilter (never {@code null})
	 */
	ClassFilter getClassFilter();

	/**
	 * 返回这个切点的MethodMatcher。
	 * @return the MethodMatcher (never {@code null})
	 */
	MethodMatcher getMethodMatcher();


	/**
	 *  始终匹配的经典指针实例。
	 */
	Pointcut TRUE = TruePointcut.INSTANCE;

}
